Based on listings that I have seen with the TotUp/Mn value, it appears that this number represents the total square footage of both the "upper" and "main" levels. So, 933 SQFT on the upper level and 1109 SQFT on the main level equals the 2042 SQFT for the TotUp/Mn.
I would think that the "upper" floor is a second story of the structure and not necessarily a finished attic. A photo of the property could help confirm or deny this.
Also, on the listings that I have seen with a value for "Lower SQFT", they always have a basement, not a crawlspace or slab. This would indicate that the lower square footage is showing the unfinished basement in the listing you referred to.
So, to answer your question directly... Based on the information you provided, the 3042 square footage does in fact seem to include the unfinished basement.
If anyone thinks I am way off on this, please correct me and give Jennelle the proper answer.